diff --git a/.gitignore b/.gitignore
index 0cca571..03190ae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@ build/**
 .gradle/**
 out/**
 .idea/**
-.composite-enable
\ No newline at end of file
+.composite-enable
+gradle.properties
\ No newline at end of file
diff --git a/.travis.yml b/.travis.yml
index 2c38b37..d7dcb9a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,19 +12,16 @@ cache:
 stages:
 - name: test
 - name: build
-- name: snapshot
-  if: branch = master
 - name: release
   if: branch = release
+before_script:
+  git checkout ${TRAVIS_BRANCH} # to fix issue with Grgit if travis checks out HEAD
 jobs:
   include:
   - stage: test
-    script: "./gradlew test"
+    script: "./gradlew test -PcheckoutIfCloned=true"
   - stage: build
-    script: "./gradlew build -x test"
-  - stage: snapshot
-    script: "./gradlew publish -x test -Dnexus.user=$NEXUS_USER -Dnexus.key=$NEXUS_KEY
-      -Dbuild.number=$TRAVIS_BUILD_NUMBER"
+    script: "./gradlew build -x test -PcheckoutIfCloned=true"
   - stage: release
     script: "./gradlew publish -x test -Ddisablesnapshot=true -Dnexus.user=$NEXUS_USER -Dnexus.key=$NEXUS_KEY
       -Dbuild.number=$TRAVIS_BUILD_NUMBER"
diff --git a/GRADLE_BUILD.md b/GRADLE_BUILD.md
new file mode 100644
index 0000000..e853715
--- /dev/null
+++ b/GRADLE_BUILD.md
@@ -0,0 +1,32 @@
+# Composite Build
+The **upb.crypto** libraries, except for **math** all depend on at least one of the other libraries.
+Often times, when developing for example **craco**, you might also be doing some changes to **math**.
+To include these changes faster, we make extensive use of Gradle`s [composite build](https://docs.gradle.org/current/userguide/composite_builds.html) feature.
+To make this easier to use, we have a composite build script contained in ``settings.gradle`` that decides when to enable composite builds and when not.
+It also serves to enable composite builds on the Travis CI.
+
+## Default Script Behaviour
+By default, the script will automatically clone **upb.crypto** dependencies that are not stored in the local file system yet.
+It clones them to the same folder that the top-level folder of the library being built is contained in.
+Furthermore, it checks that the branch names match. 
+If the library is on branch ``branch1`` and a dependency is on ``branch2``, the script will complain and tell you to checkout out branch ``branch1`` in the dependency's git.
+If no such branch exists, the library will instead want to use the ``master`` branch.
+
+You can customize this behaviour via the properties detailed in the following section.
+
+## Customizing the Script via Properties
+The composite build script can be customized via the following properties. 
+The parameters can be set via the ``gradle.properties`` file or set via command line as detailed [here](https://docs.gradle.org/current/userguide/build_environment.html). 
+
+- ``useCurrentBranch``: If defined (any value), will cause the composite build to use the currently
+    checked out branch of the dependencies.
+- ``checkoutIfCloned``: If defined (any value), will automatically check out the corresponding
+    dependency branch (branch with same name) given that the dependency was freshly cloned.
+    Used by the Travis CI to automatically switch to the right dependency branch for the build.
+    
+An example ``gradle.properties`` file:
+```
+useCurrentBranch=""
+```
+Here, ``useCurrentBranch`` is enabled by giving it an empty String value.
+
diff --git a/build.gradle b/build.gradle
index 996fce5..f3ae6c2 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,7 +1,6 @@
 plugins {
     // Apply the java-library plugin to add support for Java Library
     id 'java-library'
-    id 'maven'
     id 'maven-publish'
 }
 
@@ -62,8 +61,7 @@ test {
 
 //packaging tests
 task packageTests(type: Jar) {
-    classifier = 'tests'
-    baseName = project.name + '-test'
+    archiveClassifier = 'tests'
     from sourceSets.test.output+sourceSets.test.allSource
 }
 
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 0d4a951..62d4c05 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 2d9c86b..4c5803d 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
-#Mon Oct 29 17:01:07 CET 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-all.zip
diff --git a/gradlew b/gradlew
index cccdd3d..fbd7c51 100755
--- a/gradlew
+++ b/gradlew
@@ -1,5 +1,21 @@
 #!/usr/bin/env sh
 
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
 ##############################################################################
 ##
 ##  Gradle start up script for UN*X
@@ -28,7 +44,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
@@ -66,6 +82,7 @@ esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
+
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
@@ -109,10 +126,11 @@ if $darwin; then
     GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
 fi
 
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin ; then
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    
     JAVACMD=`cygpath --unix "$JAVACMD"`
 
     # We build the pattern for arguments to be converted via cygpath
@@ -138,19 +156,19 @@ if $cygwin ; then
         else
             eval `echo args$i`="\"$arg\""
         fi
-        i=$((i+1))
+        i=`expr $i + 1`
     done
     case $i in
-        (0) set -- ;;
-        (1) set -- "$args0" ;;
-        (2) set -- "$args0" "$args1" ;;
-        (3) set -- "$args0" "$args1" "$args2" ;;
-        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
     esac
 fi
 
@@ -159,14 +177,9 @@ save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
-APP_ARGS=$(save "$@")
+APP_ARGS=`save "$@"`
 
 # Collect all arguments for the java command, following the shell quoting and substitution rules
 eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
 
-# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
-if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
-  cd "$(dirname "$0")"
-fi
-
 exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
index f955316..a9f778a 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -1,84 +1,104 @@
-@if "%DEBUG%" == "" @echo off
-@rem ##########################################################################
-@rem
-@rem  Gradle startup script for Windows
-@rem
-@rem ##########################################################################
-
-@rem Set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" setlocal
-
-set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
-set APP_BASE_NAME=%~n0
-set APP_HOME=%DIRNAME%
-
-@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
-
-@rem Find java.exe
-if defined JAVA_HOME goto findJavaFromJavaHome
-
-set JAVA_EXE=java.exe
-%JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto init
-
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:findJavaFromJavaHome
-set JAVA_HOME=%JAVA_HOME:"=%
-set JAVA_EXE=%JAVA_HOME%/bin/java.exe
-
-if exist "%JAVA_EXE%" goto init
-
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:init
-@rem Get command-line arguments, handling Windows variants
-
-if not "%OS%" == "Windows_NT" goto win9xME_args
-
-:win9xME_args
-@rem Slurp the command line arguments.
-set CMD_LINE_ARGS=
-set _SKIP=2
-
-:win9xME_args_slurp
-if "x%~1" == "x" goto execute
-
-set CMD_LINE_ARGS=%*
-
-:execute
-@rem Setup the command line
-
-set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
-
-@rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
-
-:end
-@rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
-
-:fail
-rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
-rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
-
-:mainEnd
-if "%OS%"=="Windows_NT" endlocal
-
-:omega
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
index 92db598..db2f49c 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1 +1,78 @@
-rootProject.name = 'protocols'
\ No newline at end of file
+plugins {
+    id 'org.ajoberstar.grgit' version '4.0.2' apply false
+}
+import org.ajoberstar.grgit.Grgit
+
+rootProject.name = 'protocols'
+def msgPrefix = rootProject.name + " settings: "
+
+// do specific snapshot dependency resolution for snapshot builds
+if (!Boolean.valueOf(System.getProperty("disablesnapshot"))) {
+    def compositeLibraries = ["upb.crypto.math", "upb.crypto.craco"]
+    for (String lib : compositeLibraries) {
+        def libPrefix = "dependency " + lib
+        def libPath = file("../" + lib).getPath()
+        def grgitLib
+        def cloned
+        if (file(libPath).exists()) {
+            println(msgPrefix + libPrefix + ": Local repository exists.")
+            grgitLib = Grgit.open(dir: libPath)
+            cloned = false
+        } else {
+            println(msgPrefix + libPrefix + ": Local repository does not exist. Cloning to " + libPath + ".")
+            grgitLib = Grgit.clone(dir: libPath, uri: "https://github.com/upbcuk/" + lib + ".git")
+            cloned = true
+        }
+        def grgitThis = Grgit.open(dir: rootProject.projectDir)
+        def branchThis = grgitThis.branch.current()
+        if (hasProperty("useCurrentBranch")) {
+            println(msgPrefix + libPrefix + ": Parameter 'useCurrentBranch' is set. Using branch '" + grgitLib.branch.current().getName() + "'.")
+        } else {
+            if (file(libPath + "/.git/refs/heads/" + branchThis.getName()).exists()) {
+                if (grgitLib.branch.current().getName() == branchThis.getName()) {
+                    println(msgPrefix + libPrefix + ": Branch '" + branchThis.getName() + "' exists and is checked out already.")
+                } else {
+                    throw new GradleException(msgPrefix + libPrefix + ": Branch '" + branchThis.getName() + "' exists but is not checked out. "
+                            + "Please check it out yourself before building.")
+                }
+            } else {
+                println(msgPrefix + libPrefix + ": Branch '" + branchThis.getName() + "' does not exist locally.")
+                if (grgitLib.branch.list { mode = "REMOTE" }.collect { it.getName() }.contains("origin/" + branchThis.getName())) {
+                    if (hasProperty("checkoutIfCloned") && cloned) {
+                        println(msgPrefix + libPrefix + ": Branch '" + branchThis.getName() + "' exists but is not checked out. "
+                                + "'checkoutIfCloned' is set. Automatically checking it out.")
+                        grgitLib.checkout {
+                            branch = branchThis.getName()
+                            startPoint = "origin/" + branchThis.getName()
+                            createBranch = true
+                        }
+                    } else {
+                        throw new GradleException(msgPrefix + libPrefix + ": Branch '" + branchThis.getName()
+                                + "' exists remotely but not locally. Please check it out yourself before building.")
+                    }
+                } else {
+                    println(msgPrefix + libPrefix + ": Branch '" + branchThis.getName() + "' does not exist remotely. Using master.")
+                    if (grgitLib.branch.current().getName() == "master") {
+                        println(msgPrefix + libPrefix + ": Branch master is checked out already. Using it.")
+                    } else {
+                        if (hasProperty("checkoutIfCloned") && cloned) {
+                            println(msgPrefix + libPrefix + ": Branch master is not checked out. "
+                                    + "'checkoutIfCloned' is set. Automatically checking it out.")
+                            grgitLib.checkout {
+                                branch = branchThis.getName()
+                                startPoint = "origin/" + branchThis.getName()
+                                createBranch = true
+                            }
+                        } else {
+                            throw new GradleException(msgPrefix + libPrefix + ": Branch master exists but is not checked out. "
+                                    + "Please check it out yourself before building.")
+                        }
+                    }
+                }
+            }
+        }
+
+        println(msgPrefix + libPrefix + ": Enabling composite build.")
+        includeBuild(libPath)
+    }
+}